BACKGROUND OF THE INVENTION
Field of the Invention
[0001] The invention relates to wireless communication, and more particularly to methods
for scheduling and transmitting the UCI and wireless communication devices utilizing
the methods.
Description of the Related Art
[0002] With rapid developments in the cellular mobile communication industry, the fifth-generation
(5G) mobile communication system is obtaining increasing attentions. Recently, the
5G has been formally named by the ITU as IMT-2020 and it is expected to enter the
commercial phase in 2020. Unlike traditional 2G / 3G / 4G mobile cellular systems,
the 5G system will no longer only be human-oriented, and will have better support
for a variety of "Machine Type Communication (MTC)" users. Among the plurality of
services for serving the MTC user, there is one called Massive MTC (MMC). The main
features of the MTC user equipment served by this kind of MMC service are as follows:
(1) low cost, which is much lower than smartphones; (2) huge number (10
6 connections will be supported per square kilometer according to the requirements
of ITU for 5G and MMC services); (3) low data transfer rate requirements; and (4)
a high tolerance for latency.
[0003] In cellular communication for legacy user equipment, cell coverage is typically considered
to be about 99% when designing the system. An uncovered 1% user can utilize the mobility
of the user equipment itself to obtain service through cell selection or cell reselection.
Unlike traditional human-oriented user equipment, some types of MMC user equipment
may be deployed in relatively fixed locations, such as the MTC user equipment that
serves public facilities (street lights, water, electricity, gas meters, etc.). This
type of MMC user equipment has almost no mobility characteristics. Therefore, when
designing the MMC communication system, the cell coverage is usually required to reach
99.99% or higher. Even worse, MMC users of this type may be deployed in scenarios
with severe path loss, such as in a basement. Therefore, in order to support better
coverage, the target Maximum Coupling Loss (MCL) adopted by the MMC system design
is usually 10dB to 20dB greater than a traditional cellular system. For example, in
the standardization work of the 3GPP Rel-13 Narrow Band Intemet-of-Things (NB-IoT)
system, the cell MCL target reaches 164dB or above.
[0004] In the NB-IoT system, there are very few available subcarriers in the frequency domain.
For example, there are only 12 subcarriers in the 180 kHz system bandwidth with 15
kHz subcarrier spacing. In addition, because of the simplification of the capability
of the NB-IoT user equipment, some physical layer processes and designs in legacy
LTE system cannot be applied. Therefore, comparing to the LTE system, design for narrowband
resources in physical layer and other layers, especially the scheduling and transmission
methods and corresponding devices for uplink control resource UCI in the NB-IoT and
future technology are required.
BRIEF SUMMARY OF THE INVENTION
[0005] In view of this, methods and wireless communication devices for scheduling UCI are
provided.
[0006] In a novel aspect, the invention provides a method for scheduling UCI resources for
a user equipment. The method comprises: receiving, by the UE, downlink control information
(DCI); determining, by the UE, the position of a UCI resource region corresponding
to a physical downlink share channel (PDSCH) signal scheduled by the DCI according
to a predefined rule. The UCI resource region comprises a plurality of UCI resources
in a time domain and/or a frequency domain. The method further comprises transmitting
an ACK/NACK signal corresponding to the PDSCH signal in the UCI resource region.
[0007] In another novel aspect, the invention provides a wireless communication device for
scheduling a UCI resource. The wireless communication device comprises a radio transceiver
performing wireless transmission with at least a base station; and a controller connected
to the radio transceiver. The controller is configured to receive downlink control
information (DCI), and determine the position of a UCI resource region corresponding
to a physical downlink share channel (PDSCH) signal scheduled by the DCI according
to a predefined rule. The controller is further configured to transmit an ACK/NACK
signal corresponding to the PDSCH signal in the UCI resource region, wherein the UCI
resource region comprises a plurality of UCI resources in a time domain and/or a frequency
domain.
[0008] The UCI scheduling methods and the wireless communication devices provided by the
invention are applicable to NB-IoT and forthcoming systems that require the narrowband
resources design in the physical layer and other layers. A person skilled in the art
may understand that the summary is not intended to limit the scope of the invention,
and the scope of the invention is based on the claims.
BRIEF DESCRIPTION OF DRAWINGS
[0009] The invention can be more fully understood by reading the subsequent detailed description
and examples with references made to the accompanying drawings, wherein:
FIG. 1 is a block diagram of a wireless communication environment implemented according
to an embodiment of the invention;
FIG. 2A is a block diagram of a wireless communication device 200 according to an
embodiment of the invention;
FIG. 2B is a block diagram of a base station 300 according to an embodiment of the
invention;
FIG. 3 is a flow chart of a method for allocating UCI resources in a time-frequency
domain;
FIG. 4 is a schematic diagram of determining the UCI resource region based on the
ending sub-frame of the PDSCH signal transmission;
FIG. 5 is a schematic diagram of determining the UCI resource region based on the
ending sub-frame of a downlink scheduling window;
FIG. 6 is a schematic diagram of determining the UCI resource region based on the
ending sub-frame of the PDCCH signal transmission;
FIG. 7 is a schematic diagram of determining the UCI resource region based on the
ending sub-frame of a PDCCH search space;
FIG. 8 is a schematic diagram of determining the UCI resource region based on the
position of an uplink scheduling window;
FIG. 9 is a schematic diagram of determining the UCI resource region based on an indication
field in the DCI;
FIG. 10 is a schematic diagram of determining the UCI resource region based on an
indication field in the DCI;
FIG. 11 is a flow chart of a method for designing UCI transmission;
FIG. 12 is another flow chart of a method for designing UCI transmission; and
FIG. 13 is a flow chart of a method for aperiodic CSI reporting.
DETAILED DESCRIPTION OF THE INVENTION
[0010] The following description is of the best-contemplated mode of carrying out the invention.
This description is made for the purpose of illustrating the general principles of
the invention and should not be taken in a limiting sense. The scope of the invention
is best determined by reference to the appended claims.
[0011] With reference to the figures and the following descriptions, the features of the
embodiments of the invention will become apparent. These embodiments are only exemplary
and not limiting to the present invention. In order to enable those skilled in the
art to easily understand the principles and implementation manners of the present
invention, the NB-IoT system is taken as an example to describe the embodiments of
the present invention. However, it should be understood that the embodiments of the
present invention are not limited to the above scenarios. The embodiments are also
applicable to other systems that involve the UL ACK / NACK or other UCI transmissions.
[0012] The invention proposes a method for transmitting an uplink (UL) Acknowledgment /
Negative Acknowledgment (ACK / NACK) for the NB-IoT and other systems. For example,
unlike the LTE system, a signal processing procedure which is similar to that of a
Physical Uplink Shared Channel (PUSCH), that is, generating information bit->encoding->scrambling->modulating,
is adopted. The difference between the PUSCH and the proposed method is in that there
is no Cyclic Redundancy Code (CRC), and the encoding schemes will be different. In
addition, the ACK / NACK transmission resources in the NB-IoT system may also be different
from the LTE system. For example, it may occupy only one subcarrier in the frequency
domain and occupy multiple sub-frames in the time domain. In addition, the UCI resource
of an NB-IoT system may not support carrying multiple UCI transmissions by Code Division
Multiplexing (CDM). The UCI resource allocation method also differs from that of the
LTE system. For example, UCI resources are allocated in two dimensions, that is, in
a time domain and a frequency domain. One possible UCI resource allocation method
is to carry an indication field in the DCI which is utilized for scheduling the PDSCH,
so as to indicate the time-frequency domain location of the UCI resource. Triggering
of the aperiodic Channel Status Information (CSI) reporting of the NB-IoT system may
also be different from that of the LTE system. For example, the aperiodic CSI reporting
may be triggered within a DCI for scheduling a PDSCH.
[0013] In the embodiment of the invention, the term "UCI resource" is used for convenience
of description. In the field, other expressions such as "UL ACK / NACK resource",
"HARQ-ACK resource of DL PDSCH", "PUCCH resource", "NB-PUCCH resource" and the like,
can also be used. Therefore, the embodiment of the invention is not limited thereto.
[0014] FIG. 1 is a block diagram of a wireless communication environment implemented according
to an embodiment of the invention. In one embodiment, the wireless communication environment
100 may comprise a plurality of wireless communication devices (e.g. the wireless
communication device 110, the wireless communication device 111 and the wireless communication
device 113 shown in FIG. 1) and a service network 130. The wireless communication
device 110, the wireless communication device 111 and the wireless communication device
113 are wirelessly connected to the service network 130 to obtain the mobile service.
Each of the wireless communication device 110, the wireless communication device 111,
and the wireless communication device 113 may be referred to as user equipment. In
one embodiment, the wireless communication device 110 and the wireless communication
device 111 may be the UEs with mobility, such as a feature phone, a smartphone, a
personal tablet, a laptop, or any other computing device that can support the wireless
communication technology adopted by the service network 130. In another embodiment,
the wireless communication device 113 may be the UE without mobility or with low mobility.
For example, it may be the UE that is deployed in a relatively fixed location and
serves in the MMC. More specifically, it may be the UE applied to a public facility
(such as a street lamp, a water meter, a power meter, a gas meter, or the like), or
the UE applied to a domestic facility (such as a desk lamp, an oven, a washing machine,
a refrigerator). The UE serving in the MMC / MTC (e.g., the wireless communication
device 113) has almost no mobility.
[0015] In one embodiment, the serving network 130 may be the network of an LTE / LTE-A /
LTE-U (LAA) / TD-LTE / 5G / IoT / LTE-M / NB- IoT / EC-GSM / WiMAX / WCDMA. The service
network 130 may comprise an access network 131 and a core network 132. The access
network 131 is responsible for processing radio signals, achieving the radio protocols,
and connecting the wireless communication device 110, the wireless communication device
111 and the core network 132. The core network 132 is responsible for managing mobility,
network side authentication, and is a public / external network (e.g., the Internet)
interface.
[0016] In one embodiment, each of the access network 131 and the core network 132 may comprise
one or more network nodes with the above mentioned functions. For example, the access
network 131 may be the Evolved Universal Terrestrial Radio Access Network (hereinafter
referred to as E-UTRAN) that comprises at least two evolved NodeBs (e.g., macro cell
/ macro eNBs, pico cell / pico ENBs, or femto cell / femto eNBs). The core network
132 may be the Evolved Packet Core (EPC) that comprises a Home Subscriber Server (HSS),
a Mobility Management Entity (MME), a Serving Gateway (hereinafter referred to as
S-GW), and a Packet Data Network Gateway (hereinafter referred to as PDN-GW or P-GW),
but the invention is not limited thereto.
[0017] As shown in FIG. 1, the wireless communication device 110 is located within the coverage
area of the cell A and within the coverage area of the cell B. That is, the wireless
communication device 110 is located in the overlapped coverage area of cell A and
cell B. The wireless communication device 111 is only located within the coverage
area of the cell A. The access network 131 may comprise an eNB 131-a and an eNB 131-b
serving in the cell A and the cell B. The eNB 131-a and the eNB 131-b may be cellular
base stations that communicate with UEs. The eNB may be the cellular station wirelessly
communicating with multiple UEs, or may be a base station, an Access Point (AP), or
the like. Each eNB provides specific communication coverage for a particular geographic
area. In 3GPP, "cell" may be considered as the specific communication coverage area
of one eNB.
[0018] In an embodiment, the access network 131 may be a Heterogeneous Network (hereinafter
referred to as HetNet). The HetNet may comprise different types of eNBs, such as macro
eNBs, pico eNBs, femto eNBs, relays, and the like. The macro eNB covers a relatively
large geographic area (e.g., a geographical area with radius of several kilometers)
and allows unrestricted access to subscription services between UE and network providers.
The pico eNB covers a relatively small geographic area and allow unrestricted access
to subscription services between UE and network providers. The femto eNB is provided
in a relatively small geographic area (e.g., a home or small office) in a residential
category. Besides unrestricted access, a femto eNB may also provide restricted access
for the UE (e.g., the UE in a closed subscriber group (CSG), the UE used by a user
in a home, etc.) associated with the femto eNB.
[0019] FIG. 2A is a block diagram of a wireless communication device 200 according to an
embodiment of the invention. The wireless communication device 200 may be the user
equipment shown in the embodiment of FIG. 1. The wireless communication device 200
may comprise a radio transceiver 210, a controller 220, a storage device 230, a display
device 240 and an input / output device 250. The controller 220 is respectively connected
to the radio transceiver 210, the storage device 230, the display device 240 and the
input / output device 250.
[0020] In one embodiment, the radio transceiver 210 is configured to perform both wireless
transmissions and the transmission and reception with the access network 131, and
may comprise an interference cancellation and suppression receiver. The radio transceiver
210 may comprise a radio frequency (RF) processing device 211, a baseband processing
device 212 and an antenna 213. The RF processing device 211 is respectively connected
to the baseband processing device 212 and the antenna 213. In this embodiment, the
transmitting end of the RF processing device 211 receives the baseband signal from
the baseband processing device 212, and converts the received baseband signal into
an RF signal to be sent by the antenna 213 later. The frequency band of the RF signal
may be a frequency band of 900 MHz, a frequency band of 2100 MHz or a frequency band
of 2.6 GHz used in LTE / LTE-A / TD-LTE technology, or may be a frequency band of
1800 MHz, a frequency band of 900MHz, a frequency band of 800MHz or a frequency band
of 700MHz used by NB-IoT / LTE-M, or may also be a frequency band used by other wireless
communication technology. In this embodiment, the transmitting end of the RF processing
device 211 may comprise at least a power amplifier, a mixer and a low-pass filter,
but the invention is not limited thereto.
[0021] In one embodiment, the receiving end of the radio frequency processing device 211
receives the RF signal through the antenna 213, and converts the received RF signal
into a baseband signal for further processing by the baseband processing device 212.
The frequency band of the radio frequency signal may be a frequency band of 900 MHz,
a frequency band of 2100 MHz or a frequency band of 2.6 GHz used in LTE / LTE-A /
TD-LTE technology, or may be a frequency band of 1800 MHz, a frequency band of 900MHz,
a frequency band of 800MHz or a frequency band of 700MHz used by NB-IoT / LTE-M, or
may also be a frequency band used by other wireless communication technology. In this
embodiment, the receiving end of the RF processing device 211 may comprise multiple
hardware devices for processing RF signals. For example, the receiving end of the
RF processing device 211 may comprise at least a low noise amplifier, a mixer (also
called a down-converter), or a low-pass filter, but the invention is not limited thereto.
The low noise amplifier is configured to perform noise processing on the RF signal
received from the antenna 213. The mixer is configured to perform a frequency down
conversion operation on the RF signal that has been processed by the low noise amplifier.
[0022] In one embodiment, the baseband processing device 212 is configured to perform baseband
signal processing and is configured to control communication between a Subscriber
Identity Module (SIM) and the RF processing device 211. The baseband processing device
212 may comprise a plurality of hardware components to perform the baseband signal
processing such as an analog to digital converter, a digital to analog converter,
an amplifier circuit related to gain adjustment, a modulation / demodulation related
circuit, an encoding / decoding related circuit and so on. A person skilled in the
art may understand that the baseband processing device may further comprise multiple
modules (not shown in the figure) implemented by software, firmware or hardware, or
any combination thereof to further implement the functions of the invention. For example,
a DCI decoding module for decoding the received DCI, and a UCI decoding module for
deciding on the position of a UCI resource region corresponding to a PDSCH signal
scheduled by the DCI according to the received DCI and further processing the UL control
information by repeated encoding and scrambling for later transmission.
[0023] In one embodiment, the controller 220 may be a general purpose processor, a micro
control unit (MCU), an application processor, a digital signal processor or any type
of processor control device that processes digital data. The controller 220 may comprise
a plurality of circuits for providing functions such as data processing and calculation,
controlling the radio transceiver 210 to wirelessly communicate with the access network
131, storing data into and retrieving data from the storage device 230, transmitting
a sequence of the frame data (e.g., the frame data representing messages, graphics,
images) to the display device 240 and receiving signals from the input / output device
250. In particular, the controller 220 may cooperate with the operations of the radio
transceiver 210, the storage device 230, the display 240, and the input-output device
250 to perform the proposed method of the invention.
[0024] In another embodiment of the invention, the controller 220 may be incorporated in
the baseband processing device 212 to be a baseband processor.
[0025] In one embodiment, the storage device 230 is a non-transitory machine-readable storage
medium. The storage device 230 may comprise memories (e.g., flash memory, non-volatile
random access memory), magnetic storage devices (e.g. the hard disc, the magnetic
tape, or optical disk), or any combination thereof for storing instructions and /
or program code for the proposed methods, applications and/or protocols of the invention.
[0026] In an embodiment, the display device 240 may be a Liquid-Crystal Display (LCD), a
Light-Emitting Diode (LED) display, or an Electronic Paper Display (hereinafter referred
to as EPD) and the like. Alternatively, the display device 240 further comprises one
or more touch sensors disposed thereon or below for sensing touch, contacting or proximity
of a target (e.g., a finger or stylus).
[0027] In one embodiment, the input / output device 250 may comprise one or more buttons,
a keyboard device, a mouse, a touchpad, a video camera, a microphone and / or a speaker,
etc., as a human-machine interface for interacting with the user (Man-Machine Interface,
hereinafter referred to as MMI)
[0028] It should be understood that the various components described in the FIG. 2A embodiment
are for illustration only, and are not intended to limit the scope of the invention.
[0029] FIG. 2B is a block diagram of a base station 300 according to an embodiment of the
invention. The base station 300 may be a network device at the network-side and comprise
a radio transceiver 360, a controller 370, a storage device 380, and a wired communication
interface 390. The controller 370 is respectively connected to the radio transceiver
360, the storage device 380, and the wired communication interface 390. The RF processing
device 361, the baseband processing device 362 and the antenna 363 of the radio transceiver
360 are similar to the RF processing device 211, the baseband processing device 212
and the antenna 213 of the radio transceiver 210 described in FIG. 2A. Therefore,
the detailed descriptions are omitted here.
[0030] In one embodiment, the controller 370 may be a general purpose processor, an MCU,
an application processor, a digital signal processor, or the like. The controller
370 may comprise a plurality of circuits for providing functions such as data processing
and calculation, controlling the radio transceiver 360 to wirelessly communicate with
the wireless communication devices 110, 111 and 113, storing data into and retrieving
data from the storage device 380, and transmitting/receiving messages from other network
entities through the wired communication interface 390. In particular, the controller
370 cooperates with the described operations of the radio transceiver 360, the storage
device 380, and the wired communication interface 390 to perform the proposed method
of the invention.
[0031] In another embodiment, the controller 370 may be incorporated into the baseband processing
device 362 to be a baseband processor.
[0032] Those with ordinary skill in the art will appreciate that depending on the various
functions and operations, the circuitry of controller 220 or controller 370 may generally
comprise a plurality of transistors to control the operation of the circuitry. As
will be further understood, the particular architecture or connection of the transistor
is typically decided by a compiler, such as a Register Transfer Language (RTL) compiler.
The RTL compiler can operate in a script similar to the assembly language by a processor,
so as to compile the script into a format that can be used in the circuit layout of
the final circuit. In fact, RTL is well known for its role and purpose in promoting
the design of electronic and digital systems.
[0033] In one embodiment, the storage device 380 may be a non-transitory machine-readable
storage medium. The storage device 330 may comprise memories (e.g., flash memory,
non-volatile random access memory), magnetic storage devices (e.g. the hard disc,
the magnetic tape, or optical disk), or any combination thereof for storing instructions
and / or program code for the proposed methods, applications and/or protocols of the
invention.
[0034] In one embodiment, the wired communication interface 390 is responsible for providing
the functionality for communicating with other network entities (e.g., MMEs and S-GWs)
in the core network 132. The wired communication interface 390 may comprise a cable
modem, an Asymmetric Digital Subscriber Line (ADSL) modem, a Fiber-Optic Modem (FOM),
and / or an Ethernet interface.
Embodiment 1 (the procedure for determining the UCI resource allocated in the time-frequency
domain by the network side)
[0035] In an embodiment, as shown in FIG. 3, a method for a UE to determine the UCI resources
allocated in a time-frequency domain by the network side is provided. The method comprises
the following steps. In step S302, a user equipment (e.g. the antenna 213 of the wireless
communication device 200) receives DCI from a network device at the network side (for
example, the base station 300), and receives a PDSCH signal scheduled by the DCI.
The DCI is carried in the Physical Downlink Control Channel (PDCCH) signal. In step
S304, the UE (for example, the controller 220 of the wireless communication device
200) determines, according to a predefined rule, a position of the UCI resource region
corresponding to the PDSCH signal in a time domain and / or a frequency domain. The
UCI resource region comprises a plurality of UCI resources in a time domain and/or
a frequency domain. In step S306, the UE (for example, the controller 220 of the radio
communication device 200) determines, according to an indication field in the DCI
(also called a UCI resource indication field (for indicating the UCI resources)),
a time and / or frequency domain position of a UCI resource in the UCI resource region.
In step S308, the UE transmits (for example, the controller 220 of the radio communication
device 200 transmits through the antenna 213) the ACK / NACK information corresponding
to the PDSCH signal on the UCI resource for reporting the decoding result of the PDSCH
signal to the network device.
[0036] In one example, a UCI resource region may comprise a plurality of UCI resources in
the time domain and a plurality of UCI resources in the frequency domain. The network
device may allocate UCI resources in both the time and frequency domains. When the
physical resources in the UCI resource region are not allocated for UCI transmission,
the network device may allocate them for the PUSCH transmission. That is, the UCI
resource scheduling and the PUSCH resource scheduling may share the same physical
resource region.
[0037] In an example, the UE needs to determine the position, including time domain position
and frequency domain position, of the corresponding UCI resource in the UCI resource
region according to a dedicated DCI indication field (that is, the UCI resource indication
field) when transmitting the UL ACK / NACK. The dedicated DCI indication field is
comprised in the DCI for scheduling the PDSCH. That is, when a DCI schedules the PDSCH,
it also carries a DCI field for indicating a UCI resource to carry the ACK / NACK
information transmission of this PDSCH.
[0038] In one example, the UCI resources may also be referred to as PUCCH resources or UL
ACK / NACK resources. One UCI resource corresponds to a Physical Radio Block (PRB)
for transmitting ACK / NACK information of the PDSCH, and the physical resource block
can only carry the UL ACK / NACK transmission of one UE. That is, the UL ACK/ NACK
transmission between the UEs can only be multiplexed in the time or frequency domain.
The size of a UCI resource (that is, the number of resource elements (REs) included
in a physical resource block) is predefined, and some of the REs are used for Demodulation
Reference Signal (DMRS). The number of REs for DMRS and their positions are predefined,
and the remaining REs may be used for UL ACK / NACK information transmission.
[0039] In one example, there is only one pattern of UCI resources. For example, one subcarrier
in the frequency domain and two sub-frames in the time domain. In another example,
there may be a plurality of UCI resource patterns. For example, one or more subcarriers
in the frequency domain and one or more sub-frames in the time domain. The number
of REs contained in each pattern may be the same or almost the same. In one example,
which UCI resource pattern is to be used may be configured in a semi-static way (semi-statically
configured), e.g., using a higher layer signaling configuration. In another example,
which UCI resource pattern is to be used may be configured in a dynamic way (dynamically
configured). For example, using a DCI indication field for configuration, and the
DCI indication field is comprised in the DCI for scheduling the PDSCH.
[0040] In one example, the number of REs comprised in one UCI resource may be smaller than
the number of REs comprised in a minimum resource unit (RU) for PUSCH transmission.
For example, one UCI resource may comprise one subcarrier and two sub-frames, that
is, comprising 28 REs. The minimum resource unit for PUSCH transmission may comprise
one subcarrier and 8 sub-frames, that is, comprising 112 REs. In another example,
the number of REs comprised in one UCI resource is the same as the number of REs comprised
in the minimum resource unit for PUSCH transmission, and the resource patterns are
also the same.
[0041] In one example, one UCI resource is only used for transmitting 1-bit UL ACK / NACK
information, which may also be referred to as UL ACK / NACK resource. In another example,
one UCI resource may be used for a hybrid transmission of any one or more of UL ACK
/ NACK, CSI, and Scheduling Request (SR).
[0042] One UCI resource region may comprise multiple UCI resources in the frequency domain.
In one example, the frequency domain size of the UCI resource region is 180 kHz. Assuming
that one UCI resource occupies one subcarrier, when the subcarrier spacing is 15 kHz,
12 UCI resources are allocated in the frequency domain. When the subcarrier spacing
is 3.75 kHz, 48 UCI resources can be allocated in the frequency domain.
[0043] One UCI resource region may comprise multiple UCI resources in the time domain. In
one example, the time-domain size for UCI resource allocation is 10 sub-frames. Assuming
that one UCI resource occupies 2 sub-frames. When allocating the UCI based on the
number of UCI resources comprised in 10 sub-frames, 10/2 = 5 UCI resources may be
allocated in the time domain. When allocating the UCI based on the position of the
starting sub-frame of the UCI resource, that is, each sub-frame in the 10 sub-frames
can be used as a starting sub-frame of the UCI resource, 10 UCI resources may be allocated
in the time domain. The UCI resource region being used has a time domain size of (10
+ N-1) sub-frames and N is the number of sub-frames occupied by one UCI resource.
[0044] In one example, the time-frequency domain sizes of the UCI resource region are predefined,
for example, there are 12 subcarriers in the frequency domain and 4 sub-frames in
the time domain. In another example, the time-frequency domain size of the UCI resource
region is semi-statically configured, for example, through a cell-specific or UE-specific
high-level signaling configuration. In yet another example, the frequency domain size
of the UCI resource region is predefined and the time domain size of the UCI resource
region is semi-statically configured. In yet another example, the time domain size
of the UCI resource region is predefined and the frequency domain size of the UCI
resource region is semi-statically configured.
Embodiment 2 (the method for determining the position of a UCI resource region according
to a predefined rule)
[0045] In one embodiment, a method for determining a UCI resource region according to a
predefined rule is provided. The method comprises: the UE (for example, the controller
220 of the wireless communication device 200) determines a position of a reference
sub-frame. A time span between a starting sub-frame of the UCI resource region and
the reference sub-frame is a predefined value, a semi-statically configured value,
or a dynamically configured value.
[0046] In one example, based on the time span which is a predefined value, a semi-statically
configured value, or a dynamically configured value as described above, the UE may
decide the position of the starting sub-frame of the UCI resource region according
to the position of the reference sub-frame. The UCI resource allocation will take
the starting sub-frame as a reference point. For example, the DCI for scheduling the
PDSCH carries an indication field for indicating that the position of the starting
sub-frame of the UCI resources is
ki(
i=0,1,...,
K-1). That is, the DCI dynamically indicates that one sub-frame in the K sub-frames
(
K≥2) is the starting sub-frame of the UCI resources, where K is a predefined value.
For each
i, the value of
ki is a predefined value or a semi-statically configured value. Here, the position
ki of the sub-frame is obtained by taking the starting sub-frame of the UCI resources
as the reference point. That is, the starting sub-frame of the UCI resource region
is
n, and the actual starting sub-frame of the allocated UCI resources is
n+
ki.
[0047] In another example, UCI resource allocation is not taking the starting position of
one resource region as a reference point, but taking a reference sub-frame as a reference
point. For example, an indication field is carried in the DCI for scheduling the PDSCH,
so as to indicate that a starting sub-frame position of a UCI resource is
ki(
i=0,1,...,
K-1)
. That is, the DCI dynamically indicates that one sub-frame in the K sub-frames (
K≥2) is the starting sub-frame of the UCI resources, where K is a predefined value.
For each
i, the value of
ki is a predefined value or a semi-statically configured value. Here, the position
ki of the sub-frame is obtained by taking a reference sub-frame as the reference point.
That is, the reference sub-frame is
n, and the actual starting sub-frame of the allocated UCI resources is
n+
ki. The reference sub-frame here may be the ending sub-frame of the transmission of the
corresponding PDSCH signal, the ending sub-frame of the transmission of a PDCCH signal
which carries the DCI, the ending sub-frame of a search space of the PDCCH signal
comprising corresponding DCI or the ending sub-frame of a downlink scheduling window
comprising transmission of the PDSCH signal.
[0048] In one example, the reference sub-frame may be one downlink sub-frame. The spacing
between the downlink subcarriers is 15 kHz. The duration of the downlink sub-frame
is 1 ms, and the time span between the reference sub-frame and the starting sub-frame
of the UCI resource region is 12 ms. When the spacing between the uplink subcarriers
is 15 kHz, and the reference sub-frame is n, then the starting sub-frame of the UCI
resource region is n + 13. When the spacing between the uplink subcarriers is 3.75
kHz, the duration of the uplink sub-frame is 4 ms, the time span between the reference
sub-frame and the starting sub-frame of the UCI resource region should be at least
12 ms. The starting sub-frame of the UCI resource region is an uplink sub-frame closest
to the reference sub-frame that meets this requirement. That is, the actual time span
between the reference sub-frame and the starting sub-frame of the UCI resource region
may be greater than 12 ms and may be dynamically changed within 12 to 15 ms.
[0049] In an example, as shown in FIG. 4, the reference sub-frame is an ending sub-frame
(i.e., the last sub-frame) of the corresponding PDSCH transmission. If the PDSCH is
a repeated transmission, the reference sub-frame is the ending sub-frame of the last
repeated PDSCH transmission. The time span between the starting sub-frame of the UCI
resource region and the ending sub-frame of the corresponding PDSCH transmission is
a predefined value, such as 12 ms. In another example, the time span is a semi-statically
configured value or a dynamically configured value.
[0050] In another example, as shown in FIG. 5, the reference sub-frame is an ending sub-frame
(i.e., the last sub-frame) of a downlink scheduling window comprising the corresponding
PDSCH transmission. If the PDSCH is a repeated transmission, the reference sub-frame
is the ending sub-frame of a downlink scheduling window comprising the last repeated
PDSCH transmission. The time span between the starting sub-frame of the UCI resource
region and the ending sub-frame of the downlink scheduling window comprising the corresponding
last PDSCH transmission is a predefined value, such as 12 ms. In another example,
the time span is a semi-statically configured value or a dynamically configured value.
In an example, the downlink scheduling window may comprise the PDCCH region and the
PDSCH region. In another example, the downlink scheduling window may comprise only
the PDSCH region.
[0051] In another example, as shown in FIG. 6, the reference sub-frame is the ending sub-frame
(i.e., the last sub-frame) of a PDCCH transmission carrying a corresponding DCI. If
the PDCCH is a repeated transmission, the reference sub-frame is the ending sub-frame
of the last repeated PDCCH transmission. The time span between the starting sub-frame
of the UCI resource region and the ending sub-frame of the PDCCH transmission signal
carrying the DCI is a semi-statically configured value. In another example, the time
span is a dynamically configured value.
[0052] In another example, as shown in FIG. 7, the reference sub-frame is an ending sub-frame
(i.e., the last sub-frame) of a PDCCH search space (SS) comprising the corresponding
DCI. If the PDCCH is a repeated transmission, the reference sub-frame is the ending
sub-frame of the PDCCH search space comprising the last PDCCH transmission. The time
span between the starting sub-frame of the UCI resource region and the ending sub-frame
of the PDCCH search space carrying the DCI is a semi-statically configured value.
In another example, the time span is a dynamically configured value.
[0053] In another example, as shown in FIG. 8, the UCI resource region is a predefined region
in the uplink scheduling window, for example, at the end or the beginning of the uplink
scheduling window. In an example, the uplink scheduling window and the downlink scheduling
window carrying the corresponding PDSCH transmission correspond to the same PDCCH
search space. In another example, after the uplink scheduling window corresponds to
the PDCCH search space carrying the DCI, the next corresponding scheduling window
is used for scheduling the UCI resource. That is, after a PDCCH search space corresponds
to an uplink scheduling window n for scheduling the PUSCH resources, the next corresponding
scheduling window (n+1) is used for scheduling the UCI resource corresponding to the
PUSCH.
Embodiment 3 (a method for determining a time domain position and/or a frequency domain
position of a UCI resource according to the DCI indication field)
[0054] In one embodiment, a method for determining a UCI resource according to an indication
field of the DCI is provided. The method comprises: indicating a time domain position
and/or a frequency domain position of a UCI resource, or indicating an offset value
of a time-domain position and / or an offset value of a frequency-domain position
of one UCI resource by an indication field (that is, a UCI resource indication field)
of the DCI transmitted by the network side.
[0055] In one example, information of the time domain position and the frequency domain
position of the UCI resource may be independently encoded. That is, the UCI resource
indication field may comprise two independent subdomains, respectively indicating
the time domain position information and the frequency domain position of the UCI
resource. For example, the time domain position information may indicate
Ntime kinds of possibilities, and the frequency domain position information may indicate
Nfreq kinds of possibilities, and the number of bits corresponding to the two subdomains
may be ┌log
2(
Ntime)┐ and |log
2(
Nfreq)|, respectively. In another embodiment, the time domain position information and
the frequency domain position information of the UCI resource may be jointly encoded.
For example, the time domain position information may indicate
Ntime kinds of possibilities, and the frequency domain position information may indicate
Nfreq kinds of possibilities, and the number of bits corresponding to the joint indication
field may be |log
2(
Ntime*
Nfreq)|. Or, in a simple way, a joint index table may be used, where each index corresponds
to a time-domain position and a frequency-domain position.
[0056] In one example, there is no binding relationship between the time domain position
information and the frequency domain position information of the UCI resource indicated
in the DCI indication field. For example, the time domain position information may
indicate
Ntime kinds of possibilities, and the frequency domain position information may indicate
Nfreq kinds of possibilities, and the number of bits required by the DCI indication field
for indicating the information is at least |log
2(
Ntime*
Nfreq)|. In another example, there is some binding relationship between the time domain
position information and the frequency domain position information of the UCI resource
indicated in the DCI indication field. For example, the time domain position information
may indicate
Ntime kinds of possibilities, and the frequency domain position information may indicate
Nfreq kinds of possibilities, and the number of bits required by the DCI indication field
for indicating the information will be less than |log
2(
Ntime*
Nfre)|. That is, a certain value indicated by the DCI indication field implies both the
time domain position information and the frequency domain position information. In
one example, the UCI resource indication field indicates the entire time domain position
and frequency domain position of a UCI resource. That is, the time-frequency domain
position of the UCI resource can be uniquely determined without any additional information.
For example, there are 12 possible positions in the frequency domain and 2 possible
positions in the time domain. Then, 5 bits can be utilized to indicate the UCI resources.
[0057] In one example, as shown in FIG. 9 and FIG. 10, the UCI resource indication field
indicates a frequency domain position of a UCI resource in a UCI resource region.
For example, a subcarrier out of 12 subcarriers is indicated. In addition, the UCI
resource indication field further indicates a time domain position of a UCI resource
in the UCI resource region. For example, in FIG. 9, a UCI resource indication field
indicates that a certain sub-frame in the UCI resource region is taken as a starting
sub-frame of the UCI resources. For example, a sub-frame out of 4 sub-frames is indicated.
For example, in FIG. 10, the UCI resource indication field indicates one of a plurality
of UCI resources included in the UCI resource region in the time domain as the UCI
resource. For example, one out of two UCI resources in the time domain is indicated.
[0058] In another example, the UCI resource indication field indicates an offset value of
a time domain position and an offset value of a frequency domain position of a reference
UCI resource, and the time-frequency domain position of the reference UCI resource
is a semi-statically configured or implicitly decided. Here, the semi-static configuration
is implemented through UE-specific high-level signaling. The implicit decision can
be made as follows: implicitly determining the position of the time-frequency domain
of the UCI resource based on the index number of the starting sub-frame corresponding
to the PDSCH transmission; implicitly determining the position of the time-frequency
domain of the UCI resource based on the Cell Radio Network Temporary Identifier (C-RNTI)
value; implicitly determining the position of the time-frequency domain of the UCI
resource based on the starting Control Channel Element (CCE) index corresponding to
the PDCCH transmission, where the CCE index is a number in the entire PDCCH search
space; implicitly determining the position of the time-frequency domain of the UCI
resource based on a starting sub-frame index of the corresponding PDCCH transmission.
[0059] In another example, the UCI resource indication field indicates one of a set of UCI
resources, and the time-frequency domain positions of the set of UCI resources are
semi-statically configured. For example, four or eight UCI resources are semi-statically
configured through UE-specific high-layer signaling, and two or three bits are used
in the DCI to indicate that one of the UCI resources is used for the current UCI transmission.
[0060] In another example, the UCI resource indication field only indicates the time domain
position of the UCI resource, and the frequency domain position of the UCI resource
is configured semi-statically or decided implicitly, where the implicit decision is
performed in the same way as described above.
[0061] In another example, the UCI resource indication field only indicates the frequency
domain position of the UCI resource, and the time domain position of the UCI resource
is configured semi-statically or decided implicitly, where the implicit decision is
performed in the same way as described above.
[0062] In one example, the DCI indication field indicates entire information of the frequency
domain position and there are
Ntone subcarriers in the system bandwidth. The subcarrier index indicated by the DCI indication
field is
k,0≤
k≤
Ntone-1. In one example,
Ntone=12. In another example,
Ntone=48.
[0063] In an example, the DCI indication field indicates an offset value of the reference
frequency domain position information, and the reference frequency domain position
information is semi-statically configured or implicit decided. For example, there
are four possible offset values {0, +1, +2, -1}. Assuming that the reference subcarrier
index is
k,0≤
k≤
Ntone-1, and
Ntone is the total number of subcarriers in the system bandwidth. If the offset value is
0, it means that the allocated subcarrier position is
k. If the offset value is +2, it means that the allocated subcarrier position is mod(
k+2,
Ntone).
[0064] In an example, the above reference frequency domain position information is semi-statically
configured by UE-specific high-layer signaling. In another example, the above reference
frequency domain position information is implicitly determined. For example, the value
k is determined based on the C-RNTI value
nRNTI of the UE, where
k=mod(
nRNTI,Ntone). In another example, the value
k is determined by the starting CCE value
nCCE of the corresponding PDCCH transmission, where
k=mod(
nCCE,
Ntone). The value of
nCCE is the number of the entire PDCCH search space. Suppose that the PDCCH search space
occupies
Nsf sub-frames, one sub-frame comprises two CCE, then 0≤
nCCE≤2*
Nsf-1. For example, the value
k is determined based on the ending sub-frame
nsf of the corresponding PDSCH transmission, where
k=-mod(
nsf,Ntone). Suppose that the radio frame number of the sub-frame is
nframe, (0≤
nframe≤1023), the sub-frame number in the radio sub-frames is
nsubframe, (0≤
nsubframe≤9), then
nsf =
nframe*10+
nsubframe.
[0065] In one example, the DCI indication field indicates one of a set of frequency domain
position information, and the set of frequency domain position information is a semi-statically
configured. For example, there are 12 subcarriers in the system bandwidth, and each
set of frequency domain position information comprises 4 subcarriers. There are three
sets of configurable frequency domain position information: {0, 3, 6, 9}, {1, 4, 7,
10} {2, 5, 8, 11}.
[0066] In one example, the DCI indication field indicates entire information of a time-domain
position, such as indicating one out of
NstartSF predefined starting sub-frame positions, where
ti, (0≤
i≤
NstartSF-1). For example,
NstartSF = 4. In one example,
ti ∈ {0,1,2,3}. In another example,
ti ∈ {0,2,4,8}. When
ti = 0, the time span between the starting sub-frame position and the ending sub-frame
of the PDSCH transmission is a predefined value, for example, 12 ms.
[0067] In an example, the DCI indication field indicates an offset value of reference time
domain position information, and the reference time domain position information is
a semi-statically configured. For example, there are four possible offset values {0,
+1, +2, +3}, and the reference time domain position information semi-statically configured
via the upper layer is
ti ∈ {0,8,16,32}. When
ti = 0, the time span between the starting sub-frame position and the ending sub-frame
of the PDSCH transmission is a predefined value, for example, 12 ms.
[0068] In one example, the DCI indication field comprises 4 bits. For example, 2 of which
are used to indicate frequency domain position information, 2 bits are used to indicate
time domain position information. In another example, 4 bits are used to indicate
frequency domain position information. The time domain position information is implicitly
determined by the ending sub-frame of the PDSCH transmission.
Embodiment 4 (UCI transmission design based on repetitive encoding)
[0069] In one embodiment, as shown in FIG. 11, a method for designing UCI transmission based
on repetitive encoding is provided. The method comprises the following steps. In step
S1102, the UE (for example, the controller 220 of the wireless communication device
200) generates information bits corresponding to the ACK / NACK according to the decoding
result of the PDSCH. In step S1104, the UE repeatedly encodes the generated information
bits. In step S1106, the UE performs scrambling on the encoded bit stream. In step
S1108, the UE performs modulation on the scrambled bit stream. In step S1110, the
UE maps the modulated symbol onto the corresponding UCI resource.
[0070] In this embodiment, some SC-FDMA symbols of a UCI resource are occupied by the DMRS.
That is, the flow of processing the UCI transmission is similar to that of the PUSCH
except that there is no CRC and the encoding scheme is different. For example, the
PUSCH adopts a turbo encoding scheme, and the UCI adopts a repetitive encoding scheme.
In one example, the DMRS location, the DMRS generating method, and the DMRS density
used by the UCI transmission are consistent with the PUSCH. In another example, the
DMRS location and DMRS generating method used by the UCI transmission are consistent
with the PUSCH but the DMRS density is higher than the PUSCH. For example, for PUSCH
transmission, there is one SC-FDMA symbol per time slot for the DMRS. As to UCI transmission,
there are 2 or 3 SC-FDMA symbols per time slot for DMRS.
[0071] In an example, the number
Linf of information bits of UL ACK / NACK is 1. For example, {1} indicates ACK, and {0}
indicates NACK. In another example, the number
Linf of information bits of UL ACK / NACK is 2. For example, {10} indicates ACK, {01}
indicates NACK.
[0072] The repetitive encoding is to repeatedly encode the information bits until the number
of bits after the repetition is the number of encoded bits that can be carried by
one UCI resource. The number of times the information bits are repeated depends on
a ratio of the number of encoded bits that can be carried by one UCI resource and
the number of information bits, that is
Nrepeat=┌
Lcoded/
Linf┐.
Nrepeat is the number of repetitions,
Lcoded is the number of encoded bits that can be carried by one UCI resource and
Linf is the number of information bits. When the number of encoded bits that can be carried
by one UCI resource is not an integer multiple of the number of information bits,
the last repetition is a portion of one repetition.
[0073] The number of encoded bits that can be carried by one UCI resource is related to
the modulation scheme and the number of REs that can be mapped. For example, one UCI
resource corresponds to one subcarrier and two sub-frames, each sub-frame comprises
two time slots, each time slots comprises 7 SC-FDMA symbols. That is, one UCI resource
comprises 28 REs. Assuming that there are 3 SC-FDMA symbols in each time slot for
DMRS, a total number of 16 REs can be used for UCI data mapping. Suppose that PI (π)
/ 2 BPSK modulation is adopted, a UCI resource can carry 16 encoded bits .
[0074] In an example, the number
Linf of information bits of the UL ACK / NACK is 1. If the number of encoded bits that
can be carried by one UCI resource is 16, the repetitive encoding is repeated 16 times.
For example, the repeatedly encoded bit stream corresponding to ACK is {1111111111111111},
and the repeatedly encoded bit stream corresponding to NACK is {0000000000000000}.
In another example, the number
Linf of information bits of the UL ACK / NACK is 2. If the number of encoded bits that
can be carried by one UCI resource is 16, the repetitive encoding is repeated 8 times.
For example, the bit stream after repetitive encoding corresponding to the ACK is
{1010101010101010}, and the bit stream after repetitive encoding corresponding to
the NACK is {0101010101010101}.
[0075] In one example, the pseudo-random sequence used for scrambling is generated by a
Gold sequence of length 31 as shown in equation (1) below, the initialization thereof
is related to the cell ID, the C-RNTI value of the UE and the starting sub-frame of
the UCI resource.

where
Nc=1600, the first m sequence x
1(·) should be initialized by
x1(0)=1,
x1(
n)=0,
n=1,2,...,30, and the second m sequence x
2(·) should be initialized by

In an example,

In another example,

Here,
nRNTI is the C-RNTI value of the UE,

is the physical ID of the cell and
nsf is the index (0∼9) of the starting sub-frame of the UCI resource.
[0076] In one example, the modulation scheme is fixed to PI/2 BPSK. In another example,
the modulation scheme may be PI/2 BPSK or PI/4 QPSK. In an example, modulation scheme
is semi-statically configured, for example, through high-layer signaling configuration.
In another example, modulation scheme is dynamically configured. For example, the
DCI indicates which modulation scheme is used. In another example, the modulation
scheme depends on the number of information bits. For example, when the number of
information bits is less than or equal to a certain predefined value, PI/2 BPSK modulation
is adopted. When the number of information bits is greater than or equal to a certain
predefined values, then PI/4 QPSK modulation is adopted.
[0077] When a UCI resource comprises a plurality of subcarriers and a plurality of sub-frames,
the UCI data mapping may take a number of ways. In one example, UCI data mapping over
the entire UCI resource follows the rule of mapping in the time domain first and then
mapping in the frequency domain. In another example, the UCI data mapping is a sub-frame-by-sub-frame
mapping, and the mapping in each sub-frame follows the rule of mapping in the time
domain first and then mapping in the frequency domain.
Embodiment 5 (UCI transmission design based on symbol sequence)
[0078] In one embodiment, as shown in FIG. 12, a UCI transmission design based on symbol
sequence is provided. The method comprises following steps. In step S1202, the UE
(for example, the controller 220 of the wireless communication device 200) generates
a symbol sequence corresponding to the ACK / NACK according to the decoding result
of the PDSCH. In step S1204, the UE performs phase rotation on the generated symbol
sequence. In step S1206, the UE maps the phase-rotated symbol sequence onto a corresponding
UCI resource.
[0079] In this embodiment, the UCI transmission is not based on DMRS. That is, the entire
UCI resource is used for symbol sequence mapping, and the length of the symbol sequence
is equal to the number of available REs contained in one UCI resource.
[0080] In one example, two symbol sequences corresponding to the ACK and the NACK have orthogonality,
and the Hamming distance of the two symbol sequences is M / 2, where M is the length
of the symbol sequence. For example, if one UCI resource occupies one subcarrier and
one sub-frame, that is, one UCI resource includes 14 available REs, the symbol sequence
corresponding to ACK is {11111111111111}, and the symbol sequence corresponding to
NACK is {1111111-1-1-1-1-1-1-1}.
[0081] In this embodiment, the symbol sequence is phase rotated, so as to randomize inter-cell
interference. In one example, the symbol sequence is phase rotated according to equation
(2):

Here,

is the number of SC-FDMA symbols comprised in one time slot. For a normal CP, the
value is 7. For an extended CP, the value is 6.
ns is the index (0-19) of one time slot in a radio frame, / is the index (0 to 6) of
a SC-FDMA symbol in one time slot.
Embodiment 6 (a method for aperiodic CSI reporting)
[0082] In the NB-IoT system, considering the signaling overhead and relative stationary
of UE, there is no need to support periodic CSI reporting. However, aperiodic CSI
reporting may be supported when better coverage is met. For aperiodic CSI reporting,
the PMI and RI need not to be reported, and only the CQI value is reported. Therefore,
the number of bits required for aperiodic CSI reporting depends only on the number
of elements in the CQI table. For example, 2/3 bits indicate 4/8 CQI values. With
such a small amount of payload information, aperiodic CSI reporting may be carried
by UL ACK / NACK instead of by PUSCH. The following embodiments provide a method for
aperiodic CSI reporting carried by UL ACK / NACK transmission.
[0083] In an embodiment, as shown in FIG. 13, an aperiodic CSI reporting method is provided.
The method comprises following steps. In step S1302, the UE receives a DCI and a PDSCH
scheduled by the DCI. In step S1304, the UE determines whether CSI reporting is triggered
according to a first indication field in the DCI. In step S1306, the UE determines
a time domain and / or a frequency domain position of a UCI resource according to
a second indication field in the DCI. In step S1308, the UE transmits corresponding
UCI information on the UCI resource, where the UCI information is hybrid information
of ACK / NACK of the PDSCH and CSI, or only ACK / NACK information of the PDSCH.
[0084] In this embodiment, the CSI report is triggered by one indication field in the DCI
for scheduling the PDSCH. If the indication field is True, then the UCI information
to be transmitted is a mixture of the CSI and the ACK / NACK information of the PDSCH.
If the indication field is False, then the UCI information to be transmitted is only
the ACK / NACK information of the PDSCH. That is, CSI reporting may be triggered or
not, but the ACK / NACK information corresponding to the PDSCH will be transmitted.
[0085] Regardless of whether CSI reporting is triggered, a same physical transmission method
for transmitting the UCI is used. For example, as described in the foregoing embodiment
4, the processing flow is as follows: information bit generation → repetition encoding
of information bits → scrambling of the encoded bit stream → modulating of the scrambled
bit stream → mapping of modulated symbols onto UCI resources.
[0086] In an example, a difference corresponding to whether CSI reporting is triggered is
that the number of information bits would be different. If the UCI information is
only ACK / NACK information, only one information bit is used. For example, {1} indicates
ACK, {0} represents NACK. If the UCI information is a mixture of ACK / NACK and CSI,
the information bits are multiple information bits. For example, three information
bits may be used. The first information bit represents ACK / NACK and the last two
information bits represents 4 CQI values.
[0087] In an example, when the ACK / NACK and the CSI are mixed, in order to improve the
detection performance of ACK / NACK, the number of information bits occupied by ACK
/ NACK is equal to that of CSI. For example, for a total of four information bits,
the first two information bits represent ACK / NACK and the last two information bits
represents 4 CQI values. For example, {11} represents ACK, {00} represents NACK, or
{10} represents ACK, {01} represents NACK.
[0088] Whether the CSI is triggered affects the number of information bits carried by the
UCI. When the UCI resource contains a certain number of REs, the number of repetitions
used for repeated encoding may be different. That is, when the CSI and the ACK / NACK
are mixed transmitted, the equivalent coding rate will decrease, which will affect
the detection performance. Therefore, when performing uplink power control, hybrid
transmission of the CSI and ACK / NACK requires more transmission power than the ACK
/ NACK only transmission. In addition, when UCI is configured for repeated transmissions,
CSI and ACK / NACK hybrid transmissions will require more repetitions than ACK / NACK
only transmission to achieve the same performance requirements.
[0089] In one example, when UCI is configured to be repeatedly transmitted, the high-layer
signaling semi-statically configures two numbers of repetition times (repetition number)
for the CSI and ACK / NACK hybrid transmission and the ACK / NACK only transmission,
respectively. In another example, when the UCI is configured to be repeatedly transmitted,
the higher layer signaling configures only one repetition number for ACK / NACK only
transmission, and the repetition number for the hybrid transmission of CSI and ACK
/ NACK is implicitly determined based on the repetition number configured for ACK
/ NACK only transmission. For example, the repetition number for the hybrid transmission
is twice as the configured repetition number for ACK / NACK only transmission.
[0090] While the invention has been described by way of example and in terms of preferred
embodiment, it is to be understood that the invention is not limited thereto. Those
who are skilled in this technology can still make various alterations and modifications
without departing from the scope and spirit of this invention. Therefore, the scope
of the present invention shall be defined and protected by the following claims and
their equivalents.